Corundum (variety Ruby)

Dattaw mine

Mogok Township

Mandalay Region

Burma

2.8 by 1.9 by 1.5 cm – Thumbnail specimen (fits into a 2.5 cm cube)

Corundum and ruby are both ancient names. Corundum ultimately seems to derive from the Sanskrit word kurivinda either through the Tamil kurundam or Hindi kurand. Ruby derives from the Latin ruber, meaning red. Modern gemology defines ruby as a red chromium bearing gem variety of the mineral species corundum.

This is a fine thumbnail ruby corundum from the Mogok Stone Tract. It weighs about 60 carats. While a more precise weight is desirable, a bit of attached marble means any such numbers are only estimates. A fine thumbnail consisting of 10 by 8 mm ruby crystal growing directly out of a 18 by 17 by 13 mm stubby ruby crystal. The larger crystal has an extended root, and has marble attached. There is superficial transparency to the crystals, which causes them to suffuse much light. The color has some purple (blue) in it. Typically, a gem cutter would heat this material to remove the blue overtones. This specimen would compete well in a competitive thumbnail exhibit at the Tucson Gem and Mineral Show. Fine!